Multi thread and deadlocks

Question

I am running dataload from a text file to MS SQL SRVR database. The jobs are running in multi thread mode. I am getting deadlock errors with threads.
each thread is supposed to delete records.
with single thread mode log file order is as below
1. get product to be deleted A
2. delete A
3. get product to be deleted B
4. delete B
5. get product to be deleted C
6 delete C
with multi thread mode
1. get product to be deleted A
2. get product to be deleted B
3. get product to be deleted C
4. get product to be deleted D
5. delete A
6. get product to be deleted E
7. get product to be deleted F
8. deadlock while deleteing the product B
Any clues what is going wrong here?
Here is the code for the delete method:
================================
PreparedStatement prepStatement = null;
System.out.println("get product to be deleted " + product);
prepStatement = conn.prepareStatement("delete from MYTABLE where product = ? ");
prepStatement.setString(1, product);
prepStatement.executeUpdate();
================================
Please note that only unique data is sent to each thread.
Any help is greatly appreciated.
Thanks

Answer 1

Thanks for the responses. I need to do update/insert new records after delete operation is completed. Later at the end of the db changes, i close the connection.
From my understanding deadlocks happen when both threads try to touch the same record same time. But, i am sending unique records for each thread. Unless these is somethign wrong with the query, it should always return unique values.
This is the query that sends unique records for each thread in sql srvr.
select distinct top ? columnA, columnB from MyTable where processed = 'FALSE' and columnB = ? "
This should be equivalent of oracle query
select distinct columnA, columnB from MyTable where columnB=? rownum > ? and rownum <= ?
if the top in sql srvr is equivalent to rownum in oracle then i always get distinct records and there should be no deadlocks.
Any help?
Thanks